Hi Patrik!
For many people with tinnitus, the damage to your ears will result in noises in your head! The explanations are complicated and several competing theories can be found, but most scientists believe that your brain creates the tinnitus sounds from the damage that occurs in your ear, specifically the cochlea. Your cochlea contains cilia (nerve hair or fibers) that transmit sound to your ear. If those cilia become damaged--from noise, for example--they can no longer transmit the sound. The brain, however, is listening for the sound and thus recreates it in the form of tinnitus. This is how I understand tinnitus creation in the brain. There are also many studies which examine the effect of tinnitus on your neurotransmitters and brain waves. In sum, tinnitus is generally a phenomenon that starts in your ears, but ends in your head. Of course, my explanations are over simplified. I'm sure others more knowledgeable will provide additional information.
Regarding medical treatment, you should see an ENT right away. He can see if you've damaged any visibile structures within your ear, but generally people injure their inner ear, which cannot be seen without an MRI or PET scan. (There is also a test called "otoacoustic emission testing," but I don't think it's popular.) I would ask your ENT if you are a candidate for prednisone or an injection of dexamethasone into your ear drum. Ear damage often results in inflammation. If you can stop the inflammation, perhaps you can reverse or limit the damage from noise trauma. There are many references to steroids and tinnitus on the internet, but here's a very general one to begin:
http://www.livestrong.com/article/142723-drugs-treat-tinnitus/. Please also consult this board for more information on steroids.
Others on this board have recommended HBOT (oxygen therapy). Please look up these posts. The therapy does help people, but it's important to begin it as soon as possible. There are also vitamins, amino acids, herbs, etc., that do help. If you have trouble sleeping, your might try melatonin. Again, look for information on these boards. There's lots of good things people have already written about.
Most importantly, I believe, is to see a physician. Secondly, make sure you get adequate sleep and don't panic. Over fifty percent of tinnitus cases will resolve within three months. Just make sure you doing everything to help it resolve. When I first got tinnitus, no physician wanted to help me. They said to just live with it. If you find a doctor that won't help you, find another one who will.
Good luck and stay positive!! And no more loud music. Please protect your ears or wear ear plugs!